Lake releases east and west ‘a possibility’
JACKSONVILLE — Just over a month ago, the U.S. Army Corps of Engineers was focused on water conservation in Lake Okeechobee, as March brought one of the driest months on record. Now that the rainy season is well underway, the corps is switching from the dry season strategy to the wet season strategy, Jacksonville District Commander Col. Andrew Kelly explained in a media teleconference on Monday.
Col. Kelly said there is currently no water from Lake Okeechobee flowing east to the St. Lucie River or west to the Caloosahatchee River. No water from the lake has been released east since March 2019. Beneficial flow from the lake to the Caloosahatchee during the dry season to prevent saltwater intrusion stops when rains provide sufficient local basin runoff flow at the Franklin Lock.
“We are not making any immediate changes,” the colonel explained. Beneficial releases from the lake to the Caloosahatchee are triggered by low flow at the Franklin Lock, which is 43.4 miles from the lock on Lake O at Moore Haven. If there is sufficient local basin runoff along that 43.4 miles of river to provide the minimum flow of 650 cubic feet per second (cfs) at the Franklin Lock, no water is released from the lake.
On the east side of the lake, no water from the lake has been gone to the St. Lucie River in more than a year. In fact, water lately has been moving the other direction. Since the wet season started, billions of gallons of water from runoff in the C-44 basin have back-flowed into Lake Okeechobee. Col. Kelly said this year, about 60,000 acre-feet of water (more than 19 billion gallons) have back-flowed into the lake through the S-308 water control structure (the lock at Port Mayaca).
If the lake starts rising too quickly, the water control structure at Port Mayaca will be closed, he said. If the lake level is lower than the level of the St. Lucie Canal, the water from the St. Lucie Canal can flow west into the lake or east to the St. Lucie Lock. The C-44 reservoir and STA, currently under construction, are designed to take that basin runoff in the future, so that it can be cleaned before it is released either to the lake or to the St. Lucie River. Currently that runoff, which is usually about twice as high in phosphorus as the lake water, contributes to the nutrient overload problems (which feed algae blooms) when it enters the lake or the St. Lucie River.
Col. Kelly said Lake Okeechobee is about a foot higher now than it was at this time last year, but it is too soon to predict whether any lake releases will be needed east or west this summer. There is a possibility that could happen, he said.
“This will not be a repeat of 2019,” he predicted. “We are starting to talk about what are the triggers to make releases to the east and west.”
He said corps officials are watching the hurricane predictions and the paths of named storms.
The corps laboratories in Vicksburg, Miss., will continue the algae testing and monitoring they started last year, said Col. Kelly. The Engineer Research and Development Center (ERDC) is in contact with the Florida Blue Green Algae Task Force as well as universities working on similar research.
He said the corps will seek a deviation to the Lake Okeechobee Regulation Schedule (LORS ’08) that will allow them to release water when algae is not present in large amounts and not release water when the lake has large algae blooms.
“We are still learning as we go,” he said. “We’ve got to be flexible enough to take the latest science as it comes,” he explained. The colonel said the latest science will be used in developing the Lake Okeechobee Operating System Manual (LOSOM), which will go into effect in 2022 when the repairs to the Herbert Hoover Dike are complete. LOSOM will release LORS ’08.
Col. Kelly said he has learned that “there are no average years” when it comes to Lake Okeechobee, so they have to keep their operation plans flexible. “One storm could change everything.”
South of the lake, design work continues on the Everglades Agricultural Area (EAA) reservoir.
“We’re in the middle of working on the design,” Col. Kelly said. “There have been no delays thus far.” He said the massive project will take eight to 10 years to complete, depending on federal funding availability. “We are looking forward to keeping that on an aggressive schedule,” he said. “It always depends on funding.”